Many commercial aircraft are today provided with sound systems for furnishing entertainment such as sound associated with a motion picture or stereo music, while the aircraft is in flight. Such systems may be provided with a plurality of channels for providing different modes of entertainment to different passengers while being non-disturbing to other passengers. In such systems the sound is piped from a fixed transducer through tubings to passenger's ears to enable, firstly, a substantial blockage of extraneous noise and, secondly, eliminating disturbance to other passengers. Moreover, accurate reproduction of the sound is desirable as well as the ability of the headset to conform to the physical characteristics of the head and ear span of any person who might be a passenger. The stethoscope must be light in weight, comfortable to the wearer while suspended from the ear canals and remain in position during normal head movement of the passenger. Further, inasmuch as the ear pieces of the stethoscope must be inserted in the passenger's ear canals, hygienic considerations require that the stethoscope, and particularly the ear pieces thereof, be either sterilizable or disposable and, where disposability is not required, it is desirable that the entire stethoscope be relatively inexpensive so as to reduce losses due to pilferage, misuse, breakage, and the like.
The present invention is considered to be an improvement over U.S. Pat. Nos. 3,623,571; 3,730,290; 3,776,362.